"Things To See - Really Old Plumbing"
Aqueduct Tip by goodfish

So here's a fun fact: Pompeii had running water. No kidding. An aqueduct fed lead pipes - like these in the picture - that ran to public fountains, baths and private villas. The system pretty much worked with gravity and during periods of drought, the flow could be shut off to individual areas in order of priority. Homes were the first to lose their supply and public fountains were last.

So why didn't they all keel over from lead poisoning? Heavy deposits of calcium built up inside the pipes and acted as a protective barrier between the metal and water.